As Internet and Intranet become increasingly popular, various new applications are developed. One general concern on deploying new applications is the diversity of client station capabilities.
Multicasting or broadcasting of multimedia streams is an important Internet or Intranet application with growing interests. If the same multicast stream is intended to be received by numerous client stations, then it is desirable for the multicasting station to multicast the stream based on what can be received by client stations with the least capability.
To facilitate multicasting or broadcasting, there generally are intermediate distribution nodes, referred to as reflector nodes, which receive the multicast stream and then send the stream to the client stations or other distribution/reflector nodes. These distribution nodes can in fact form a distribution hierarchy.
The prior art includes various systems directed towards modifying the multimedia stream content based on user preference on content ratings. For example, U.S. Pat. No. 5,550,575, entitled Viewer Discretion Television Program Control System," issued Aug. 27, 1996 to West et al., provides both time and content controls for multiple and variable numbers of viewers. The controls are at the granularity of the entire video.
Still another example, U.S. Pat. No. 5,434,678, Seamless Transmission of Non-Sequential Video Segments, issued Jul. 18, 1995, to Abecassis, is directed to the selective retrieval and seamless transmission of non-sequentially stored video segments of a variable content video program, responsive to a viewers pre established video content preferences. Here, video segments from a single source can be selected by applying video content preferences to a video segment map. With this approach it is desirable to generate the variable content video program and to obtain the participation of the broadcaster, if it is to be effective.
These approaches either rely on the multicast source to generate multiple streams for different content specifications, or the user and the intermediate proxy or distribution nodes to apply proper filtering on the content of a multicast stream. The client receiving capability has not been taken into consideration and the network configuration or the multicast path is not dynamically changed, i.e. it does not get reconfigured on a session basis to address the particular requirement of each multicast session.